Montreal head coach Claude Julien called his team's performance against the Carolina Hurricanes on Thursday night "unacceptable."
The Canadiens fell 4-1 to the visiting Hurricanes and saw their lead atop the Atlantic Division shrink to one point.
"Our effort and focus were unacceptable," said Julien. "We weren't on our game. We were chasing the puck all night. Hard to win games when that happens."
Montreal (41-24-9) took an early lead but Carolina (32-27-13) scored four unanswered goals to extend their point streak to nine games and keep their playoff hopes alive.
The Hurricanes are five points out of the final wild-card spot in the Eastern Conference with 10 games left in their season.
"Our execution wasn't there tonight," said Phillip Danault, who centred the first line between Max Pacioretty and Alexander Radulov. "We have to find some extra motivation. This kind of performance won't cut it in the playoffs."
Lee Stempniak scored twice and Eddie Lack stopped 21 shots for Carolina. The Hurricanes, undefeated in regulation time in nine straight games (6-0-3), also got goals from Elias Lindholm and Jeff Skinner, into the empty net.
Montreal was the slower team and failed to dictate much of the play. The Canadiens turned the puck over 22 times and only won 35 per cent of the game's faceoffs.
Defenceman Jordie Benn said the home side got complacent, especially after the early lead.
"We got slow and we got away from our game," he said. "When we're playing our game, we're pretty effective. We had a good start but we got away from it."
Alex Galchenyuk scored the lone goal for Montreal after Julien demoted him from first-line centre to third-line winger. That move paid off just minutes into the encounter when Galchenyuk scored his first goal in 10 games at 6:46.
Andrew Shaw and Galchenyuk moved in on Lack on a 2-on-1, with Shaw completing a perfect pass to his new linemate, who made no mistake for his 16th of the season.
"Chucky looked more comfortable with Shaw and it was nice to see him get rewarded with a goal there early and get his confidence up," said Pacioretty. "Now it's up to our line to produce offensively."
Lindholm extended his point streak to nine games when he scored his 10th of the season at 16:10 of the first, on the power play, to make it 1-1. With Alexei Emelin in the box for holding, Lindholm completed a gorgeous tic-tac-toe play for an easy tap-in at the side of Carey Price's net.
The Hurricanes took a 2-1 lead with 39 seconds remaining in the second period when Stempniak's harmless backhand shot took a big deflection off Emelin's skate to skip past Price.
Stempniak got his second of night at 5:11 of the third as he cashed in a 2-on-1 pass from Skinner. The goals were Stempniak's 13th and 14th of the season.
"We're a confident group and we think we can get into the playoffs," said Stempniak. "We're getting better as the season is going along. We've been on a good run here. We're playing complete games and we're not giving up much."
Skinner scored his team-leading 29th goal of the season into the empty net at 17:57 of the third.
"The guys know what's on the line," said Carolina coach Bill Peters of the playoff picture. "This is the most important time of the season. We still believe and we're going to keep going about our business."
Despite being one of the league's best third-period teams, Montreal only took five shots on net in the third.
Carolina had not beaten the Canadiens in Montreal in seven games (0-6-1) dating back to Feb. 13, 2012.
Notes: Price stopped 19-of-22 shots in defeat. … Montreal's Nathan Beaulieu was a healthy scratch for the second time in the last five games.
Kelsey Patterson, The Canadian Press